The United States of America entices thousands of tourists every year, who are all looking to discover and explore the country. To make sure you see all the USA has to offer, it’s important to plan your trip, before you set off on your adventure. You will need to consider what to pack, to ensure you can use your personal electrical appliances safely whilst abroad. This normally includes the use of a travel adaptor, which is a device that simply allows you to plug any UK electrical appliance into a foreign electrical socket. It is important to note that it does not convert the voltage or frequency. For USA there are two associated plug types, types A and B. Plug type A is the plug which has two flat parallel pins and plug type B is the plug which has two flat parallel pins and a grounding pin. USA operates on a 120V supply voltage and 60Hz. Electricity supplies worldwide can vary from anything between 100V and 240V. It can be extremely dangerous to use an electrical appliance that is rated at a voltage different from the supply. As voltage can differ from country to country, you may need to use a voltage converter or transformer whilst in USA. If the frequency is different, the normal operation of an electrical appliance may also be affected. For example, a 50Hz clock may run faster on a 60Hz electricity supply.  Most voltage converters and transformers come supplied with plug adaptors, so you may not need to buy a separate travel adaptor. All converters and transformers will have a maximum power rating (AMPS or WATTS) so make sure that any appliance you intend to use does not exceed this rating. You can determine whether you’ll need to use a converter or transformer, by looking at the appliance rating plate. A dual voltage rated appliance will display for example ‘INPUT: 110-240V’ on the body of the appliance or its power supply. This means that you will not need a converter or transformer but just a travel adaptor, because the USA operates on a 120V supply voltage, which is within the 110-240V range that the dual voltage appliance operates on. In the USA the supply voltage is 120V. If the appliance or its power supply are not dual voltage rated, the single voltage appliance will have to be used alongside a voltage transformer or converter to allow the appliance to work safely and properly (unless the appliance operates at 120V). Converters and transformers perform a similar function, but their applications differ. Converters are typically used with appliances that operate for a short duration (1-2hours), whilst most transformers can be used alongside appliances that operate continuously. It’s important to understand that some travel adaptors are not suitable for any appliances that require an earth connection. These types of travel adaptors should only be used with double insulated equipment, which will be clearly marked with the symbol shown below. We recommend you check your appliances before embarking on your journey, to understand the requirements in USA. When you subscribe, you confirm you have read Electrical Safety First's privacy policy. You may opt out of receiving email updates at any time by using the unsubscribe link in the emails.